The eight-foot-tall sculpture of a boy holding a squirming frog was commissioned to sit at the tip of the Punta della Dogana, between the Grand and the Guidecca canals in Venice. The work, by the California artist Charles Ray, is a much-loved landmark, photographed daily by scores of tourists, and was to have celebrated its fourth anniversary there next month. But the city, which controls the spot, plans to remove it on Tuesday and replace it with a reproduction of the 19th-century lamppost that formerly stood there.

“I knew things were getting serious when a friend of mine sent me a petition to keep ‘Boy With Frog,’ ” Mr. Ray said in a telephone interview from his studio in Los Angeles.

While the sculpture has its fans, it also has detractors. Although classically inspired and seemingly in keeping with much of the city’s art and architecture, some residents missed the lamppost, long a romantic meeting spot.

François Pinault, the French luxury goods magnate and collector, commissioned Mr. Ray’s sculpture, made of white-painted stainless steel, after signing a 33-year-agreement with the city to transform the 17th-century Dogana, a former customs house, into an art museum filled with work from his vast collection. It opened in June 2009, on the eve of that year’s Venice Biennale. (Mr. Pinault also oversees the 18th-century Palazzo Grassi, which he opened as an art space in 2007.)

Mr. Pinault warned Mr. Ray from the outset that the tip of the Dogana was controlled by the city and that a permit to keep it there would have to be renewed four times a year.

“Boy With Frog” has had its troubles. When protests arose after it was installed, the authorities feared that it would be vandalized, so they had it encased periodically in a transparent protective box. “To be fair, Mr. Pinault put guards surrounding it and tried to install motion detectors,” Mr. Ray said.

When it became apparent that the city envisaged removing the sculpture and an uproar broke out, Mr. Pinault offered to move “Boy With Frog” to the Palazzo Grassi, but Mr. Ray refused.

“It would look as though it took a stroll,” the artist said. “I told him to put it away for a while and we’ll talk. I feel strongly that it’s a public sculpture and should be on view, but it has to be in the right place.”

Samuele Costantini, a spokesman for the city, said the sculpture was always intended to be a temporary installation.

But Mr. Ray said: “I never saw it as temporary. I worked so hard at the scale of the sculpture so that it would be embedded in the city. I had hoped ‘The Boy’ would eventually become a citizen of Venice.”

Among the sculpture’s most vehement critics is Franco Miracco, a former member of the board of the Venice Biennale and an adviser to various Italian culture ministers who has called Mr. Pinault the “Napoleon of contemporary art.” But Mr. Costantini emphasized that no “anti-Pinault attitude” existed within the city government itself.

Francesco Bonami, an independent curator who has been a vocal supporter of the sculpture, wrote in the newspaper La Stampa that its removal would be “administrative cowardice.”

“If they put the lamppost back,” he said in a telephone interview, “it would be a symbol of cultural darkness.”

RESTITUTION AND A SALE

A mustachioed man and scantily clad woman singing by candlelight will be among the stars of Christie’s old master painting sales on June 5 in New York. They are depicted in “The Duet,” a 1624 painting by the Dutch master Gerrit van Honthorst that is expected to fetch $2 million to $3 million.

“It’s a picture with a particularly intriguing past,” said Nicholas Hall, international head of Christie’s old master paintings department. In the 19th century the painting was part of the renowned Stroganov Collection in St. Petersburg, where it hung alongside Rembrandts, Rubenses and van Dycks in the family’s palace. After the Russian Revolution of 1917, the Soviet government nationalized the palace collection, and in 1931 it sold “The Duet” at an auction in Berlin.

Later that year it was purchased by Bruno Spiro, a German Jewish arms dealer, and his wife, Ellen. Mr. Spiro was sent to a Nazi camp, where he died in 1936, and the Nazis seized the painting along with other assets and sold it in 1938. In 1969 a Munich dealer sold it to the Montreal Museum of Fine Arts.

Several years ago, the Spiros’ heirs began hunting for the painting, and in 2009 they traced it to the Montreal museum; the institution returned it to them in April.

Sometimes the departure of a museum curator becomes an occasion for the institution to rethink and reorganize. Such is the case at the Museum of Modern Art. When Connie Butler, its chief curator of drawings, decided to move to Los Angeles to become co-curator of the 2014 “Made in L.A.” biennial at the Hammer Museum and a visiting professor at the University of Southern California, MoMA’s director, Glenn D. Lowry, decided to combine the departments of prints and illustrated books and of drawings.

“As the boundaries between prints and drawings have become blurred, it made sense,” Mr. Lowry said. “The more we are immersed in the digital world, the more young artists want to make things on paper.”

Combining the departments, he explained, will benefit visitors. The two blocks of galleries — one for prints and illustrated books and the other for drawings — will be joined to produce richer and more interesting exhibitions, he said.

YET ANOTHER GAGOSIAN

The superdealer Larry Gagosian is expanding his empire again. This week he announced that he had negotiated a 20-year lease on a 22,000-square-foot space at 20 Grosvenor Hill in London’s Mayfair district. This will be its third gallery in London and his 13th worldwide.

“We’ve been looking for a bigger place in Mayfair, one that would resemble a Chelsea gallery,” Mr. Gagosian said. “And this has great space with over 15-foot-high ceilings.”

If all goes smoothly, he hopes to open the new gallery in time for London’s Frieze Art Fair in October 2014.